A multichannel thin-film optical waveguide sensor for determining aqueous biochemical concentration with a high dynamic range of measurement is proposed. The sensitivity dependence of the proposed sensor on interaction length and waveguide thickness is investigated for dye solutions and three different hemoglobin concentration levels of carboxyhemoglobins. The sensitivity is inversely proportional to the waveguide thickness while proportional to the interaction length. As a consequence the variability of the interaction length makes the proposed sensor a flexible tool for concentration measurements. Moreover, an efficient method for determining the absorption coefficient is discussed.
© 1993 Optical Society of America
Original Manuscript: February 28, 1992
Published: July 1, 1993
Shin-Won Kang, Keisuke Sasaki, and Haruyuki Minamitani, "Sensitivity analysis of a thin-film optical waveguide biochemical sensor using evanescent field absorption," Appl. Opt. 32, 3544-3549 (1993)